I think of the right to be wrong as our bedrock right, the right in which every other right is planted. I'd like to think progressives and conservatives both agree, and when it suits them they do. But it is an axiom of human nature that the impulse to correct injustice turns us into busybodies who rarely ask whether the injustice or the correction will cause more harm.

When I think of states' rights as the right of states to go their own ways on most matters, each free to design its own solution to a common problem, not because the local solution is bound to be the best solution but even though it probably isn't, I'm all for states' rights. I think it's usually fairly obvious where a line must be drawn: local solutions are unacceptable if they deny some Americans fundamental rights—such as the right to vote, or work, or go to a decent school.

I have trouble thinking of the right of corporations to donate unlimited amounts of money to political campaigns as that kind of fundamental right.

And if it isn't, then I believe any coherent theory of federalism would allow Montana to limit corporate donations to political campaigns, even though Montana might be dead wrong about those donations being harmful.

On Monday the U.S. Supreme Court ruled five to four that its 2010 ruling in Citizens United v. Federal Election Commission—that corporations should be free to contribute as they please to political campaigns—applied equally to local and federal elections. The Montana supreme court had said otherwise, declaring that Montana would continue to abide by a 100-year-old law forbidding corporations to spend money on Montana elections.

"What part of 'free speech' does the Montana Supreme Court not understand?" the Chicago Tribune editorial page smugly wondered Tuesday morning. The Tribune noted that the Montana law had been that state's response to a history of "political corruption at the hands of powerful businesses." But the editorial page then made a couple of points unworthy of it.

"It's worth pondering how powerful those corporations actually were back then if they couldn't stop the state Legislature from passing this law. It's also worth asking if the alleged mischief that took place more than a century ago sheds much light on the realities of modern politics."

In other words: (1) any law enacted to curb powerful interests can't be taken seriously, because if those interests were all that powerful the law could never have been passed. And (2), besides, if a law's a century old what good is it anyway?

A couple of years ago, by the same five-to-four margin, the Supreme Court in McDonald v. Chicago told Chicago that its handgun ban was unconstitutional. (The new gun law Chicago then passed was just struck down in part by a federal judge.)

The Court had put Mayor Daley in his place and the press crowed. "The Second Amendment couldn't be clearer," asserted John Kass about the murkiest, most internally inconsistent plank in the Bill of Rights. "Rather than denying law-abiding folks the right to self-defense, Chicago would do better to work with state and federal governments to target the illegal gun trade that arms gang-bangers, dope dealers and other criminals," wrote Steve Huntley, though the Second Amendment makes no mention of self-defense.

What bothered me then and does now is that no one wondered if Americans had just lost something precious—the freedom of local jurisdictions to make their own calls on gun control. It is an issue, surely, on which the thinking is not likely to be identical in Chicago and in, say, Montana. Before 2010, those two very different places could write two very different gun laws, and each law—tailored to local circumstances—could be equally right.